stop_machine(): stop_machine_run() changed to use cpu mask
Instead of a "cpu" arg with magic values NR_CPUS (any cpu) and ~0 (all cpus), pass a cpumask_t. Allow NULL for the common case (where we don't care which CPU the function is run on): temporary cpumask_t's are usually considered bad for stack space. This deprecates stop_machine_run, to be removed soon when all the callers are dead. Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
This commit is contained in:
parent
0432158758
commit
eeec4fad96
|
@ -5,19 +5,19 @@
|
|||
(and more). So the "read" side to such a lock is anything which
|
||||
diables preeempt. */
|
||||
#include <linux/cpu.h>
|
||||
#include <linux/cpumask.h>
|
||||
#include <asm/system.h>
|
||||
|
||||
#if defined(CONFIG_STOP_MACHINE) && defined(CONFIG_SMP)
|
||||
|
||||
/* Deprecated, but useful for transition. */
|
||||
#define ALL_CPUS ~0U
|
||||
|
||||
/**
|
||||
* stop_machine_run: freeze the machine on all CPUs and run this function
|
||||
* stop_machine: freeze the machine on all CPUs and run this function
|
||||
* @fn: the function to run
|
||||
* @data: the data ptr for the @fn()
|
||||
* @cpu: if @cpu == n, run @fn() on cpu n
|
||||
* if @cpu == NR_CPUS, run @fn() on any cpu
|
||||
* if @cpu == ALL_CPUS, run @fn() on every online CPU.
|
||||
* @cpus: the cpus to run the @fn() on (NULL = any online cpu)
|
||||
*
|
||||
* Description: This causes a thread to be scheduled on every cpu,
|
||||
* each of which disables interrupts. The result is that noone is
|
||||
|
@ -26,22 +26,22 @@
|
|||
*
|
||||
* This can be thought of as a very heavy write lock, equivalent to
|
||||
* grabbing every spinlock in the kernel. */
|
||||
int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu);
|
||||
int stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus);
|
||||
|
||||
/**
|
||||
* __stop_machine_run: freeze the machine on all CPUs and run this function
|
||||
* __stop_machine: freeze the machine on all CPUs and run this function
|
||||
* @fn: the function to run
|
||||
* @data: the data ptr for the @fn
|
||||
* @cpu: the cpu to run @fn on (or any, if @cpu == NR_CPUS.
|
||||
* @cpus: the cpus to run the @fn() on (NULL = any online cpu)
|
||||
*
|
||||
* Description: This is a special version of the above, which assumes cpus
|
||||
* won't come or go while it's being called. Used by hotplug cpu.
|
||||
*/
|
||||
int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu);
|
||||
int __stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus);
|
||||
#else
|
||||
|
||||
static inline int stop_machine_run(int (*fn)(void *), void *data,
|
||||
unsigned int cpu)
|
||||
static inline int stop_machine(int (*fn)(void *), void *data,
|
||||
const cpumask_t *cpus)
|
||||
{
|
||||
int ret;
|
||||
local_irq_disable();
|
||||
|
@ -50,4 +50,18 @@ static inline int stop_machine_run(int (*fn)(void *), void *data,
|
|||
return ret;
|
||||
}
|
||||
#endif /* CONFIG_SMP */
|
||||
|
||||
static inline int __deprecated stop_machine_run(int (*fn)(void *), void *data,
|
||||
unsigned int cpu)
|
||||
{
|
||||
/* If they don't care which cpu fn runs on, just pick one. */
|
||||
if (cpu == NR_CPUS)
|
||||
return stop_machine(fn, data, NULL);
|
||||
else if (cpu == ~0U)
|
||||
return stop_machine(fn, data, &cpu_possible_map);
|
||||
else {
|
||||
cpumask_t cpus = cpumask_of_cpu(cpu);
|
||||
return stop_machine(fn, data, &cpus);
|
||||
}
|
||||
}
|
||||
#endif /* _LINUX_STOP_MACHINE */
|
||||
|
|
|
@ -248,8 +248,9 @@ static int __ref _cpu_down(unsigned int cpu, int tasks_frozen)
|
|||
cpus_setall(tmp);
|
||||
cpu_clear(cpu, tmp);
|
||||
set_cpus_allowed_ptr(current, &tmp);
|
||||
tmp = cpumask_of_cpu(cpu);
|
||||
|
||||
err = __stop_machine_run(take_cpu_down, &tcd_param, cpu);
|
||||
err = __stop_machine(take_cpu_down, &tcd_param, &tmp);
|
||||
if (err) {
|
||||
/* CPU didn't die: tell everyone. Can't complain. */
|
||||
if (raw_notifier_call_chain(&cpu_chain, CPU_DOWN_FAILED | mod,
|
||||
|
|
|
@ -100,7 +100,7 @@ static int chill(void *unused)
|
|||
return 0;
|
||||
}
|
||||
|
||||
int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
|
||||
int __stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus)
|
||||
{
|
||||
int i, err;
|
||||
struct stop_machine_data active, idle;
|
||||
|
@ -112,10 +112,6 @@ int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
|
|||
idle.fn = chill;
|
||||
idle.data = NULL;
|
||||
|
||||
/* If they don't care which cpu fn runs on, just pick one. */
|
||||
if (cpu == NR_CPUS)
|
||||
cpu = any_online_cpu(cpu_online_map);
|
||||
|
||||
/* This could be too big for stack on large machines. */
|
||||
threads = kcalloc(NR_CPUS, sizeof(threads[0]), GFP_KERNEL);
|
||||
if (!threads)
|
||||
|
@ -128,13 +124,16 @@ int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
|
|||
set_state(STOPMACHINE_PREPARE);
|
||||
|
||||
for_each_online_cpu(i) {
|
||||
struct stop_machine_data *smdata;
|
||||
struct stop_machine_data *smdata = &idle;
|
||||
struct sched_param param = { .sched_priority = MAX_RT_PRIO-1 };
|
||||
|
||||
if (cpu == ALL_CPUS || i == cpu)
|
||||
smdata = &active;
|
||||
else
|
||||
smdata = &idle;
|
||||
if (!cpus) {
|
||||
if (i == first_cpu(cpu_online_map))
|
||||
smdata = &active;
|
||||
} else {
|
||||
if (cpu_isset(i, *cpus))
|
||||
smdata = &active;
|
||||
}
|
||||
|
||||
threads[i] = kthread_create((void *)stop_cpu, smdata, "kstop%u",
|
||||
i);
|
||||
|
@ -154,7 +153,7 @@ int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
|
|||
|
||||
/* We've created all the threads. Wake them all: hold this CPU so one
|
||||
* doesn't hit this CPU until we're ready. */
|
||||
cpu = get_cpu();
|
||||
get_cpu();
|
||||
for_each_online_cpu(i)
|
||||
wake_up_process(threads[i]);
|
||||
|
||||
|
@ -177,15 +176,15 @@ int __stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
|
|||
return err;
|
||||
}
|
||||
|
||||
int stop_machine_run(int (*fn)(void *), void *data, unsigned int cpu)
|
||||
int stop_machine(int (*fn)(void *), void *data, const cpumask_t *cpus)
|
||||
{
|
||||
int ret;
|
||||
|
||||
/* No CPUs can come up or down during this. */
|
||||
get_online_cpus();
|
||||
ret = __stop_machine_run(fn, data, cpu);
|
||||
ret = __stop_machine(fn, data, cpus);
|
||||
put_online_cpus();
|
||||
|
||||
return ret;
|
||||
}
|
||||
EXPORT_SYMBOL_GPL(stop_machine_run);
|
||||
EXPORT_SYMBOL_GPL(stop_machine);
|
||||
|
|
Loading…
Reference in New Issue
Block a user